.intro{
	width:100%;
	height:100%;
	background-color:grey;
	opacity:0.5;
	position:absolute;
	z-index:1000;
	overflow:hidden;
	top:0;
	left:0;
}

.intro .introbox{
	-moz-border-radius: 4px;
  -webkit-border-radius: 4px;
	background-color:black;
	color:white;
	width:400px;
	height:400px;
	text-align:center;
	position:relative;
	top:50%;
    left:50%;
    margin:-200px 0 0 -200px;
	
}